David Wayne Britton doesn't make excuses for his past, but he wants to make amends.

In his national television debut on "Law & Order" tomorrow, Britton, 47, plays an ex-con, a role he knows firsthand.

Britton spent 14 years in prison for robbery. Since his release a year ago, he has worked with veterans and young people and has doggedly pursued an acting career, a passion he discovered during his years at Sing Sing.

Next month, Britton will appear on stage at a Manhattan fundraiser for Rehabilitation Through the Arts, the Sing Sing theater program. Also appearing is Charles Dutton, the actor and director who turned his life around after going to prison for fatally stabbing a man in a street fight.

"Charles Dutton was more of an inspiration than he could possibly imagine," Britton said.

During the past year, Britton has appeared in Westchester performances of "The Exonerated," a play that tells the stories of six innocent death-row survivors in their own words. This month, he is appearing locally in "The Alzheimer's Monologues," a play about the impact of the disease, which is headed to the New York City Fringe Festival in the summer.

Britton, a Croton-on-Hudson resident, owes his TV break to Shirley Rich of Rye, a casting doyenne who helped launch the careers of Edward Norton, Sean Penn and Robert Downey Jr.

Rich, 83, saw him perform in the Sing Sing productions of "One Flew Over the Cuckoo's Nest" and "A Few Good Men."

"David is so gifted, a cross between Denzel Washington and Larry Fishburne," said Rich, whose film portfolio includes "Kramer vs. Kramer," "Serpico" and "Saturday Night Fever."

"I wouldn't encourage anyone to become an actor, because there are a lot of pitfalls," Rich said. "But David is so exciting on stage. He's tall, handsome, intelligent. He's got it all."

Britton's past was unknown to the staff of "Law & Order" when they cast him as Tyrell Young, a best-selling author who transformed his 14-year prison term into fodder for his tales denouncing racism and gang violence.

"That's exactly what I'm trying to do now," Britton said.

Britton has looked for opportunities to tell his story to young men who are doing poorly in school and risk failing or dropping out.

"I don't have a magic serum," he said in the Briarcliff home of his fiancee, Laura Kramer. "But I owe it to the kids to tell them my experience and let them know they will wind up the same way if they continue their behavior."

Britton spoke recently at the White Plains Youth Bureau, where director Frank Williams said he made a lasting impression.

And he's just begun a six-session video workshop for Project Earthquake, a program at Ossining High School that aims to boost the graduation rate of black males.

Britton did well in school but said the classes were unchallenging. He joined the Navy and, after he left the service in 1981, moved to New York City and coached basketball and tennis for private-school students for a while. By the mid-1980s, he had begun using cocaine and, as his habit worsened, he worked protection for drug dealers. He was arrested in 1992 on a robbery charge.

Britton already had been at Sing Sing for two years and had written a number of screenplays when Katherine Vockins, a former international marketing executive from Katonah, launched the volunteer Rehabilitation Through the Arts program in 1996. Britton became a founding member.

"The important thing is finding some sort of beauty behind those walls," Britton said.

Since his release, Britton has participated in recreational therapy programs at the Montrose Veterans Affairs hospital. Julia Anderson, chief of recreational therapy, said through storytelling and creative writing projects, Britton has established a rapport with veterans from World War II to the Iraqi conflict.

"When he reads to them, he makes the character come alive with his voice and his intonation," Anderson said. "He makes the vets feel they are not alone."

After 14 years in prison, Britton faced a changed world on the outside.

"David has learned so much so quickly," Anderson said. "He is a very strong individual. He knows what his purpose is in life, and he is fighting like mad to make it happen."

Britton exudes self-confidence when he discusses the acting projects and public-speaking engagements he has undertaken since his release.

"I don't like to be afraid of things. I like to think I can do everything," he said. But he turns pensive when he talks of how things might have gone.

"My life was put on hold to give me an opportunity to see where I was headed," he said. "I could have been dead from drugs or random violence."